A dangerous idea is like any other peril: One's first impulse on
confronting it is to fight or run away. This simple observation goes
a long way toward explaining the turbulent history of evolutionary
theory, with its threatening implications for cherished notions such
as religion, morality and human potential. Some of that turbulent
history, and a variety of views on the relation between evolution
and morality, can be sampled in three recent books: In The
Altruism Equation, biologist Lee Dugatkin gives
biographical sketches of seven major historical figures who took an
interest in the importance of blood kinship in shaping social
behavior. In Primates and Philosophers, primatologist Frans
de Waal and a group of philosophers and social theorists (Robert
Wright, Christine M. Korsgaard, Philip Kitcher and Peter Singer)
have a dialogue about the roots of morality in nonhuman species. And
in The Evolution of Morality, philosopher Richard Joyce
provides a rigorous, if preliminary, overview of what evolutionary
theory means for moral philosophy.

It is not easy to reconcile morality and altruism with evolution.
Natural selection appears to favor individuals who further
themselves at the expense of others, whereas morality is inherently
about helping others or benefiting society as a whole. Darwin
wrestled with this problem and came up with two provisional
explanations. The first grew out of the simple observation that
family members tend to share the same traits. (This is what enables
animal breeders to sacrifice some individuals but still retain their
traits by allowing their relatives to breed.) So perhaps some
individuals (honeybee workers, for example) evolve to sacrifice
their own lives so that their relatives (in the case of honeybees,
the queen) can breed. Darwin's second explanation was that groups of
altruists will be better at rounding up food, fending off predators
and so forth, giving them a decisive advantage over groups of more
selfish individuals. Darwin invoked group selection to explain the
evolution of moral behavior in humans, envisioning the groups as
entire tribes.

Dugatkin traces the history of these ideas from Darwin to the
present, culminating with a discussion of theories that express the
conditions for the evolution of altruism in mathematical terms.
Thomas Huxley, "Darwin's bulldog," regarded nature as
primarily "red in tooth and claw." In 1888, Huxley wrote
that "beyond the limited and temporary relations of the family,
the Hobbesian war of each against all was the normal state of
existence." He believed that human morality is not something
that evolved—it requires rebelling against our animal nature.
Huxley's contemporary Petr Kropotkin, the Russian prince and
anarchist, objected; he thought that Darwin and Huxley vastly
underestimated the importance of mutual aid in all kinds of groups.

From the 1920s through the 1940s, University of Chicago biologist W.
C. Alee tried, as Kropotkin had, to elevate cooperation to a grand
principle of nature. By the middle of the 20th century, evolutionary
theory had been placed on a mathematical foundation by J. B. S.
Haldane, Ronald Fisher and Sewall Wright, but these men only touched
on the problem of altruism, perhaps because they were not field
biologists and lacked direct observational experience.

According to Dugatkin, the "altruism equation" was not
fully derived until the late William D. Hamilton and George R. Price
developed their theories. Hamilton's rule, set forth in 1963, states
that natural selection favors a gene that codes for altruism over
one that does not whenever r (the coefficient of genetic
relatedness between an altruist and a recipient of altruism)
multiplied by b (the benefit that the recipient obtains) is
greater than c (the cost paid by the altruist). So in this
model the cost is balanced by benefits to close genealogical
relatives of the altruist.

Dugatkin's biographical sketches of these men are entertaining and
insightful. Historians of science will want more detail, but there
is little doubt that efforts to explain altruism and morality in
formal scientific terms are heavily influenced by the cultures and
personal histories of their proponents. Scientific progress does get
made, but it is a messy process, like the making of laws and
sausages. The more we know about the social, cultural and individual
contexts, the better.

Unfortunately, Dugatkin's account is marred by a bias of his own. He
seems to be fixated on altruism among "blood relatives" to
the exclusion of other kinds of mutual aid. This leads him to
misrepresent both history and contemporary sociobiology. By my own
estimation, altruism became narrowly associated with genealogical
relatedness during a single historical period, starting in the 1960s
with Hamilton's first papers and John Maynard Smith's
interpretation. Price's work in the 1970s is important in part
because it broadened the interpretation of r to include any
positive genetic (or even phenotypic) correlation among members of a
group—as Hamilton stressed in his 1975 reformulation of
inclusive fitness theory in terms of the Price equation.

Moreover, the thrust of modern research has been to show that high
degrees of cooperation can evolve with low values of r
(even r=0), based on mechanisms such as mutual policing.
The ultra-social behavior of social insects, for example, is no
longer thought to require ultrahigh values of genealogical
relatedness. Instead, the rb in Hamilton's equation can be
interpreted as the measure of how much the personal reproduction of
an average carrier of a gene for altruism is enhanced by help from
others, whether they are relatives or not. In recent reviews of
kin-selection theory, associating r with genealogical
relatedness is often characterized as a fallacy, so it is puzzling
that Dugatkin, who is undoubtedly familiar with the literature,
would emphasize this original definition so strongly.

In the lead essay in Primates and Philosophers, Frans de
Waal provides a historical sketch of his own (beginning with Thomas
Hobbes and Thomas Huxley) and proceeds to show how elements of
morality such as empathy, sympathy, community concern and a sense of
fairness also exist in our closest primate relatives. De Waal
describes his research as an attack on "veneer theory,"
which imagines human morality to be a thin veneer overlaying a
selfish animal nature.

Robert Wright (who says he is one of those whom de Waal labels a
veneer theorist) argues in his response that behavioral similarities
between humans and other primates conceal important psychological
differences. Ape behavior is more likely to be guided by emotions,
he believes, whereas seemingly similar human behavior is more likely
to be guided by conscious strategizing. Christine Korsgaard largely
agrees with Wright. As she puts it,

an animal that can entertain his purposes before his mind,
and perhaps even entertain thoughts about how to achieve those
purposes, is exerting a greater degree of conscious control over his
own movements than, say, the spider [going toward a moth caught in
her web], and is therefore in a deeper sense an agent.

For Wright and Korsgaard, it is agency, rather than emotionally
driven behavior, that defines human morality.

Philip Kitcher regards de Waal's "sledgehammer" approach
to veneer theory as unhelpful, because it fails to distinguish among
varieties of psychological altruism:

Until we have a clearer view of the specific kinds of
psychological altruism chimpanzees (and other nonhuman primates)
display, and until we know what kinds are relevant to morality, it's
premature to claim that human morality is a "direct
outgrowth" of tendencies these animals share.

Kitcher, like Wright and Korsgaard, wants to strike a balance
between continuity and uniqueness:

I suspect that between us and our most recent common
ancestor with the chimps there have been some very important
evolutionary steps: the emergence of a capacity for normative
guidance and self-control, the ability to speak and to discuss
potential moral resources with one another, and about fifty thousand
years (at least) of important cultural evolution.

[T]he Chinese philosopher Mozi, appalled at the damage
caused by war, asked: "What is the way of universal love and
mutual benefit?" and answered his own question: "It is to
regard other people's countries as one's own." Yet, as de Waal
points out, the practice of this more impartial morality is
"fragile." Doesn't this conception come very close to
saying that the impartial element of morality is a veneer, laid over
our evolved nature?

Primates and Philosophershas the spontaneity of a good
conversation but also some of the redundancy and disorganization.
The Evolution of Moralityis a more sustained effort to
explore the implications of evolutionary theory for moral
philosophy. Author Richard Joyce begins by reviewing the standard
theories for the evolution of altruism, before making his main
point—which is that altruism fails to capture the essence of
human morality, no matter how it evolved:

We can easily imagine a community of people all of whom
have the same desires: They all want to live in peace and harmony,
and violence is unheard of. Everywhere you look there are friendly,
loving people, oozing prosocial emotions. However, there is no
reason to think that there is a moral judgment in sight. Those
imaginary beings have inhibitions against killing,
stealing, etc. They wouldn't dream of doing such things; they just
don't want to do them. But we need not credit them with a conception
of prohibition: the idea that one shouldn't kill or steal
because to do so is wrong. And moral judgments require, among other
things, the capacity to understand prohibitions.

In Joyce's view, the kind of altruism emphasized by Dugatkin is
especially inadequate to explain human morality. After all, nepotism
is just one step away from individual selfishness in a society that
includes nonrelatives.

For Joyce, the evolutionary puzzle is to explain the human capacity
to make, enforce and abide by moral judgments. Yet the answer he
arrives at is much the same as for the evolution of altruism
envisioned by Darwin so long ago: Groups of individuals who possess
these capacities survive and reproduce better than groups that don't.

Joyce's sustained inquiry includes many interesting observations and
asides. The Evolution of Morality is the most demanding of
the three books discussed here but is also the most rewarding for
those willing to make the effort.

One of the most important distinctions in evolutionary theory is
between proximate and ultimate causation. The concepts are seldom
mentioned by name in the three books but nevertheless can be used to
summarize their contents. There is something about morality that is
inherently behavioral and other-oriented. As Joyce puts it,
"Morality seems to be designed to serve society." On the
other hand, morality cannot be defined exclusively at the behavioral
level. The proximate mechanism also matters, although agreement
about the particular magic ingredient is notoriously difficult to achieve.

This is exactly what we should expect from an evolutionary
perspective. Group-oriented behaviors have evolved in many species,
from microbes on up. Even within our own species, the 50,000 years
of cultural evolution emphasized by Kitcher could have produced very
different ways of achieving cooperation in different cultures. A
given element of morality (such as internalized guilt) might be
crucial in some cultures and peripheral or even absent in others.
This point might be especially difficult to grasp for those who base
their ideas about morality on their own intuition. When a given
phenotype can evolve by many different proximate mechanisms, it is
typical for evolutionists to regard any particular mechanism as
secondary in importance; if one is not available, another will take
its place. The one-to-many relationship inherent in the
ultimate/proximate distinction argues against basing definitions of
morality on any particular proximate mechanism.